[gtk+] texthandle: Fix handle dragging on wayland

[Carlos Garnacho <carlosg src gnome org>]

commit 73bf16b3b0492b6ac5e077f7179312c5090cfb6e
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Oct 14 15:53:51 2015 +0200

    texthandle: Fix handle dragging on wayland
    
    Text handles are subsurfaces on wayland, so sort of their own toplevel.
    This made gtk_widget_translate_coordinates() to bail out there, resulting
    in text handles being mispositioned and jumpy. To fix this, translate to
    toplevel GtkWindow coordinates manually, and translate coordinates from
    there.
    
    Along the way, the coordinates reported in ::handle-dragged have been
    fixed so there is no small jumps in either axis (most noticeable in the
    X axis when you started dragging, and in the Y axis when moving between
    lines of different heights.

 gtk/gtktexthandle.c |   31 +++++++++++++++++++++++--------
 1 files changed, 23 insertions(+), 8 deletions(-)
---
diff --git a/gtk/gtktexthandle.c b/gtk/gtktexthandle.c
index da98287..8334887 100644
--- a/gtk/gtktexthandle.c
+++ b/gtk/gtktexthandle.c
@@ -242,18 +242,33 @@ gtk_text_handle_widget_event (GtkWidget     *widget,
            event->motion.state & GDK_BUTTON1_MASK &&
            priv->windows[pos].dragged)
     {
-      gint x, y, width, handle_height;
+      gint x, y, handle_width, handle_height;
+      cairo_rectangle_int_t rect;
       GtkAllocation allocation;
+      GtkWidget *window;
 
+      window = gtk_widget_get_parent (priv->windows[pos].widget);
       gtk_widget_get_allocation (priv->windows[pos].widget, &allocation);
-      width = allocation.width;
-      _gtk_text_handle_get_size (handle, NULL, &handle_height);
+      _gtk_text_handle_get_size (handle, &handle_width, &handle_height);
+
+      _gtk_window_get_popover_position (GTK_WINDOW (window),
+                                        priv->windows[pos].widget,
+                                        NULL, &rect);
+
+      x = rect.x + event->motion.x - priv->windows[pos].dx;
+      y = rect.y + event->motion.y - priv->windows[pos].dy +
+        priv->windows[pos].border.top / 2;
 
-      x = event->motion.x - priv->windows[pos].dx + (width / 2);
-      y = event->motion.y - priv->windows[pos].dy +
-        priv->windows[pos].pointing_to.height / 2;
+      if (pos == GTK_TEXT_HANDLE_POSITION_CURSOR &&
+          priv->mode == GTK_TEXT_HANDLE_MODE_CURSOR)
+        x += handle_width / 2;
+      else if ((pos == GTK_TEXT_HANDLE_POSITION_CURSOR &&
+                priv->windows[pos].dir == GTK_TEXT_DIR_RTL) ||
+               (pos == GTK_TEXT_HANDLE_POSITION_SELECTION_START &&
+                priv->windows[pos].dir != GTK_TEXT_DIR_RTL))
+        x += handle_width;
 
-      gtk_widget_translate_coordinates (widget, priv->parent, x, y, &x, &y);
+      gtk_widget_translate_coordinates (window, priv->parent, x, y, &x, &y);
       g_signal_emit (handle, signals[HANDLE_DRAGGED], 0, pos, x, y);
     }
 
@@ -400,7 +415,7 @@ _gtk_text_handle_update (GtkTextHandle         *handle,
         rect.x -= rect.width;
 
       border->top = height;
-      border->bottom = handle_window->pointing_to.height;
+      border->bottom = height;
 
       /* The goal is to make the window 3 times as wide and high. The handle
        * will be rendered in the center, making the rest an invisible border.